Noting that the data theft and disclosure activities intended to interfere with the presidential election process could only have been directed by the highest levels of Russia’s government, President Obama said in a statement, “our diplomats have experienced an unacceptable level of harassment in Moscow by Russian security services and police over the last year. Such activities have consequences.”

The sanctions announced Thursday are directed against nine entities and individuals: the GRU and the FSB, two Russian intelligence services; four individual officers of the GRU; and three companies that provided material support to the GRU's cyber operations. The State Department also shut down two Russian compounds, in Maryland and New York, and declared "persona non grata" 35 Russian intelligence operatives.

"All Americans should be alarmed by Russia's actions," President Obama wrote in the statement.

U.S. Sen. Ben Cardin, D-Md., ranking member of the Senate Foreign Relations Committee, is calling on the Senate, the incoming administration, and the American people to take the findings seriously. In a statement, the senator says the sanctions are a good start - but not enough.

"The Russian attack on our democratic institutions is a wake-up call, a political Pearl Harbor as others have noted. I encourage my colleagues in the Senate, the incoming administration and the American people to view it as such. Now is not the "time to get on with our lives," but to take an appropriate response in line with the ongoing threat that Russia poses to our democracy and global security interests. I welcome and support the new sanctions announced by the administration today it is a good start. Sanctions have been and will remain an important tool in the United States' diplomatic arsenal to respond to attacks on our country and our allies and national security interests around the world.

"It is not, however, sufficient. The executive branch has acted, but it is imperative the legislative branch now pick up the ball and move it forward. Congressional sanctions can complement and strengthen these new executive sanctions.

Therefore because of Russia's attack on us, their destabilizing and murderous role in Syria, and their illegal annexation of Crimea and invasion of Ukraine, I continue to believe the United States must go further and that is why I am introducing two bills next month the first which would establish an independent, nonpartisan commission to further examine the attack and Russian's efforts to interfere in our election. The second bill will frame our policy on Russia to include comprehensive enhanced sanctions in response to Russia's interference in our election and its ongoing aggression in Ukraine and Syria. The bill will also increase assistance to bolster democratic institutions across Europe.

"I look forward to reading the full details from the Federal Bureau of Investigation and the Department of Homeland Security as soon as possible, and following up on any recommendations the agencies make for Congressional action. I also look forward to the Intelligence Communities broader assessment of the Russian attack, due before the Obama Administration leaves office."

President Obama says his administration will soon provide a report to Congress about Russia's efforts to interfere in the election as well as information on malicious cyber activity detected in previous elections. He noted that the actions announced Thursday will not be the "sum total" of the U.S. response to Russia's "aggressive activities."

A spokesperson for Russian President Vladimir Putin told the Associated Press that Moscow regrets the sanctions and will consider retaliatory measures.